Leases - Summary of Balance Sheet Location and Balances for Operating and Finance Leases (Detail) - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Operating leases:
Right-of-use assets - operating leases		$ 97,411	$ 0
Current operating lease liabilities		24,154	0
Long-term operating lease liabilities		95,112	0
Finance leases:
Fixed assets, net		115,564	$ 121,913
Current finance lease liabilities	[1]	$ 130
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]		us-gaap:AccruedLiabilitiesCurrent
Long-term finance lease liabilities	[2]	$ 97
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]		us-gaap:OtherLiabilitiesNoncurrent
Weighted average remaining lease term (in years)
Operating leases		6 years
Finance leases		2 years
Weighted average discount rate
Operating leases		4.60%
Finance leases		5.00%
Finance Leases [Member]
Finance leases:
Fixed assets, gross		$ 524
Accumulated depreciation		286
Fixed assets, net		$ 238

[1] Current finance lease liabilities are included in Accrued expenses within the consolidated balance sheets.

[2] Long-term finance lease liabilities are included in Other liabilities within the consolidated balance sheets.